This invention relates to a method of growing homogeneous crystals from a hydrothermal growing solution provided in a growing tank, solubility of the crystals in the growing solution decreasing with an increase in temperature (retrograde solubility), and to a device for implementation of the method, comprising one or more growing tanks containing a hydrothermal growing solution, with fixtures holding the raw material for the crystals and the crystal seeds, which tank(s) can be connected to at least one further tank by means of a tube.
The term "homogeneous" in this context refers to crystals where both crystal and crystal seed have the same crystal structure and preferably consist of the same substance, or whose lattice constants are largely identical, at least.